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This One Goes to 11: Solar Cycle Heats Up, Threatens Satellites

Solar radiation reaches an 11-year high again in 2011, making things interesting for those reliant on satellites — the U.S. military included.

As Inside the Air Forcenotes this week, the solar cycle — "the frequency in which sun spots and solar flares occur" — waxes and wanes every 11 years. The last one reached its apex in April 2000, so it’s gonna get warm again soon. And while solar flares can and do damage satellites even in non-peak times, 2011 still looms big.

Radiation from solar flares or coronal holes — areas on the sun that can cause geomagnetic storming past Earth similar to a flare — can lead to increased “drag” on satellites as well as affect communications, Crown said.

The Air Force has collected data on the space weather environment for “many years” and has characterized the natural environment in space from charged particles to radiation, Lt. Gen. Michael Hamel — commander of the Air Force Space and Missile Systems Center at Los Angeles Air Force Base — said at an April 10 briefing . . . .

“We know different orbital regimes have different characteristics, we know the degradation that happens in certain subsystems, and so we build this into the specifications and standards of the materials and the designs, and we put that margin into that so if we say . . . that a system must have a design life of 10 years, that isn’t just something that you assert; you actually have to run the tests for the components, the individual subsystems, so that you can actually statistically and predictably be able to say it’s going to live that long,” the three-star said.

During the 2003 solar flare event, a NASA-operated Martian Radiation Environment Experiment sensor was overloaded by solar activity and now is no longer functional, Crown said. In addition, another NASA asset, the Geostationary Operational Environmental Satellite-13 in Earth-orbit had “some problems with an imager” when it was saturated with a large solar flare.

“There’s countless, countless other” examples, Crown said. “There’s GPS impacts: errors in meters and location. They were temporary; they were localized and temporary. Some of them lasted three days. Off-shore drilling uses GPS, and they have to be accurate to the centimeter, and, when you’re talking about meters of error, it can really affect them.”